title: The natural occurrence of circulating antibodies in populations of endemic malarious areas.
abstract: The magnitude of humoral response to soluble antigen extracted from Plasmodium falciparum schizonts and merozoites was assessed in 744 blood samples collected from different parts of India. In this study, parasitological and immunological data were considered for assessment of antibody during natural infections at various seasons. The antibody response has been measured by enzyme-immuno assay. Survey was done in all age groups. Overall antimalarial IgG level had started increasing after five years which shows that the rate of infection was high in the small age groups. Elevated level of IgG in populations indicates that the study area is undergoing a period prevalence of the disease. In most of the individuals with active infection, IgG and IgM levels were high. Positivity in IgM denoted the active transmission of malaria. Elevated levels of antigen specific IgA was observed in some cases but the mechanism is not yet understood. Presence of circulating immune complexes during acute infection shows the failure of detection of circulating free antibodies in some individuals. The significance of findings in relation to serological status in individuals exposed naturally to malaria has been discussed.
authors.affiliation: Malaria Research Centre, Delhi, India.
authors.forename: S
authors.initials: S
authors.lastname: Biswas
authors.forename: Q B
authors.initials: QB
authors.lastname: Saxena
authors.forename: A
authors.initials: A
authors.lastname: Roy
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000936:Antigen-Antibody Complex / Q000097:blood; D003430:Cross-Sectional Studies; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007194:India / Q000453:epidemiology; D008288:Malaria / Q000453:epidemiology*; D010963:Plasmodium falciparum / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D000936:Antigen-Antibody Complex; D007074:Immunoglobulin G; D007075:Immunoglobulin M